Permanent anti-snag finish for fabrics

ABSTRACT

A method for improving the resistance of fabrics to snagging, to inhibit pilling, to improve the resistance to oil staining, to provide dimensional stability and otherwise to upgrade the properties of fabrics comprises the application thereto of an aqueous latex of a polymer of from about 25 to 50 weight percent of a hydroxy lower alkyl acrylate, from about 6 to 12 weight percent acrylonitrile from about 40 to 60 weight percent of a lower alkyl acrylate having from two to eight carbon atoms in the alkyl group and from about 1 to 5 weight percent acrylic acid wherein said polymer is of a high enough molecular weight to be insensitive to chlorinated solvents and water and after application curing the polymer on the so treated fabric.

Write Lalk et a1.

PERMANENT ANTl-SNAG FINISH FOR FABRICS Inventors: James W. Lalk, Shepherdi Jobie Cre'ar, Midland, both of Mich.

Assignee: The Dow Chemical Company,

Midland, Mich.

Filed: July 26, 1973 Appl. No.: 383,024

us. 01 117/1395 117/161 ug; 117/161 UT, 117/163 1111. c1. .1 C08j 1/44- Field of Search 117/163, 161 UC, 161 UT, l17/l39.5 A; 260/29.6 TA, 29.4 UA

References Cited UNITED STATES PATENTS 4 1957 Sanders; 260/29.6 TA 2/1960 Matlin et al 117/140 R 3,547,690 l2/l970 Nickeson et al l17/l61 UT Primary ExaminerMichael Sofocleous Assistant Examiner-Theodore G. Davis 5 7 ABSTRACT two to eight carbon atoms in the alkyl group and 'from about 1 to 5 weight percent acrylic acid wherein said polymer is of a high enough molecular weight to be insensitive to chlorinated solvents and water and after application curing the polymer on the so treated fab- 7 Claims, No Drawings PERMANENT ANTI-SNAG FINISH FOR FABRICS BACKGROUND OF THE INVENTION The recent trend in garment fabrics from the traditional woven fabrics, such as worsted, to knit fabrics hascreated some serious manufacturingproblems. For example, the present day mass production cutting techniques, as well as the new techniques, e.g., laser, available to the mens garment industry have been found substantially unusable. Previously, a manufacturer could cut many layers of fabric when employing such fabrics as the worsted. However, when knits began to be employed, because of sagging, stretching, etc., only a few layers of the fabric could be cut at one time. Knit fabrics normally require up to 24 hours to relax on the cutting table before they can be cut. This is to insure the fabric has returned to its original dimensions after being stretched as it was laid upon the cutting table. Knit fabrics generally require more time and care in handling resulting in fewer garments being constructed per hour of work.

The same problems as well as others carry over to the finished garment. One of the chief deterrents to the growth of double-, singleand wrap knit garments is their tendenc ygto snag. That tendencyis particularly troublesome with lighter weight fabrics as are used in wearing apparel; Snagging is enough-of a problem to overshadow all of the comfort features of such garments. Thus, the need for atreatment for fabrics to eliminate or at least to minimize snagging is a priority objective of the garment industry. Such a treatment should be permanent to survive dry cleaning and/or machine washing. It should not alter the hand or other desirable characteristics of the fabric. It should be easily and economically applied; Other suitable attributes will be recognized by the industry. I

SUMMARY OF THE INVENTION This invention is a method for upgradingwoven or knit textile fabrics. The method comprises the application to the fabric of an aqueous latex of a particular class of polymers followed by curing the polymer on the fabric.

A method for improving the resistance of fabrics to snagging, to inhibit pulling, to improve the resistance to oil staining, to provide dimensional stability and otherwise to upgrade the properties of fabrics comprises the application thereto of an, aqueous latex of a polymer of from about 25 to 50 weight percent of a hydroxy lower alkyl acrylate, from about 40 to 60 weight percent of a lower alkyl acrylate having from two to eight carbon atoms in the alkyl group and from about 1 to 5 weight percent acrylic acid wherein the polymer is above a statedminimum molecular weight and after application curing the polymer on the so treated fabric.

The indicated polymer represents a balance of monomeric moieties that provides a broad spectrum of advantages to the polymer and thus to the treated fabric.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The hydroxy lower alkyl acrylate contains from two to four carbon atoms in the alkyl group and is present in amount of from about to 50 weight percent of the polymer composition. When lesser amounts than 25 percent are used the resulting polymer is solvent sensitive, unduly harsh, has reduced elongation and toughness. Over 50 percent results in a water sensitive polymer.

If more than the stated amount of acrylonitrile is employed the interpolymer is stiff and hard and is not suitable for application to fabrics. Lessthan 6 percent acrylonitrile provides a polymer that is dry cleaning solvent (chlorinated solvents) sensitive.

The lower alkyl acrylate should have from two .to eight carbon atoms in the alkyl group and be present in amount of from about 40 to 60 weight percent of the polymer composition. Less than the indicated amount will give a hard polymer having water sensitivity. When the polymer contains more than 60 percent of the acrylate it is solvent sensitive and has reduced toughness.

The acrylic acid is present to provide a latent acidic function for potential crosslinking and to provide a polymerization control. lf more than 5 percent acrylic acid is used latex has reduced shelf stability and the polymer is water sensitive and hard. If less than 1 percent is employed the latex is unstable and the polymer is solvent sensitive and lacks durability.

in addition to the balance of monomers the polymer should be of a molecular weight high enough to be insensitive to chlorinated solvents. If the molecular weight is significantly lower, and. unacceptably high concentration of .a crosslinking agent is required to confer dry cleaning permanence to the treated fabric. By insensitive is meant that the properties of a film made from the polymer are not significantly changed upon exposure to chlorinated solvents or water.

Thepolymer latexes are made by conventional emulsion-polymerization technology using known emulsifiers and catalysts and known ranges of the parameters of temperature, pressure and solids.

Although most of the benefits of the invention are achieved by use of the unmodified latex, it may be desirable to add certain functional ingredients thereto-for special effects or to tailor the coating for a particular family of properties. For example, dry cleaning permanence is imparted by use of a polyfunctional compound reactive with the carboxylic or hydroxyl moieties.

Thus, a small amount of from about 2 to 5 weight percent based on the polymer of a melamine resin will improve those named properties without undesirable effect on the hand of the treated fabrics. Other useful polyfunctional agents will be known. The crosslinking reaction may be accomplished by exposure toelevated temperature of for example from 240 to 260F or by use of an acidic catalyst.

The composition can be applied by known means employed in the textile industry. Preferably the treatment is applied to the goods by spray application. Spraying results in a fabric of better hand than that resulting from" application of the same composition by padding or other conventional technique. The treat ment may be applied after dyeing and scouring and before heat setting or to'the finished fabric or even to the finished garment. It is an advantage that when the composition is applied before heat setting, the subsequent exposure to elevated temperature to set the fabric will also cure the polymer.

The composition should be applied to the fabric at a rate of about 1 to about 5 weight percent added to the fabric. Within that range the treatment does not significantly affect the esthetic characteristics or the hand of the fabric and does provide the benefits of the invention.

EXAMPLE I Scoured doubleknit fabric is passed through a conventional textile padder set to give 100 percent wet pick up of an aqueous latex containing 2 weight percent solids of a polymer of 43 percent hydroxypropyl acrylate, 9 percent acrylonitrile, 46 percent butyl acrylate and 2 percent acrylic acid ammonium salt. The latexcontained variously from 1 to 10 percent of a water soluble melamine resin sold commercially as MM83 by the Rohm and Haas Company. After drying for 5 minutes at 240F the finish was cured for 1.5 minutes at 340F.

The fabrics were tested for snagging with an lCl Mace Snagger. In that test a sleeve of the fabric is slipped over a cylinder which is rotated counterclockwise for 600 revolutions with a spiked spherical mace bouncing against the fabric. The fabric is then compared against rating standards and rated from 1 being the largest number of snags to 5 for a sample with no snags.

Each of the fabrics after exposure to the Mace Snagger was removed from the cylinder and ironed for 12 seconds with a 5 pound steam iron. The samples were then compared to the Standard Snag Photos viewed in an ASTM Pilling Viewing Box. I

The fabrics without treatment rated 2 to 3. The treated fabrics rated 4 to 5 after five dry cleanings and 30 machine washings. In addition, the treated fabrics had better dimensional stability, improved hand and drape and reduced bulking over untreated fabric.

EXAMPLE 2 In the manner of Example 1 a solid green twill doubleknit fabric rating 2.5 before treatment rated 5.0

after five dry cleanings with from 1.5 to 8.0 percent of applied anti-snag finish using 5 percent of MM83.

EXAMPLE 3 A pique doubleknit fabric was treated as in Example 1 with from 1.5 to 6 percent add-on of the polymer crosslinked with 5 percent of MM83. Before treatment the fabric had a rating of 2.0. After treatment and five dry cleanings or 30 machine washings its rating was 4.5 to 4.8.

What is claimed is:

l. A method for reducing the snagging of fabrics comprising the application to the-fabric of an aqueous latex of a polymer comprising from about 25 to 50 weight percent of a hydroxy lower alkyl acrylate, from about 6 to 12 weight percent acrylonitrile, from about 40 to 60 weight percent of a lower alkyl acrylate having from two to eight carbon atoms in the alkyl group and from about 1 to 5 weight percent acrylic acid wherein said polymer is of a molecular weight to be insensitive to chlorinated solvents and water followed by dewatering the coating and curing the polymer.

2. The method of claim 1 wherein said application of latex to the fabric is by spray application.

3. The method of claim 1 wherein said fabric is a knit fabric.

4. The method of claim 1 wherein said hydroxy lower organic compound is a water soluble melamine resin. 

1. A METHOD FOR REDUCING THE SNAGGING OF FABRICS COMPRISING THE APPLICATION TO THE FABRIC OF AN AQUEOUS LATEX OF A POLYMER COMPRISING FROM BOUT 25 TO 50 WEIGHT PERCENT ACRYLOLOWER ALKYL ACRYLATE, FROM ABOUT 6 TO 12 WEIGHT PERCENT ACRYLONITRILE, FROM ABOUT 40 TO 60 WEIGHT PERCENT OF A LOWER ALKYL ACRYLATE HAVING FROM TWO TO EIGHT CARBON ATOMS IN THE ALKYL GROUP AND FROM ABOUT 1 YO 5 WEIGHT PERCENT ACRYLIC ACID WHEREIN SAID POLYMER IS OF A MOLECULAR WEIGHT TO BE INSENSITIVE TO CHLORINATED SOLVENTS AND WATER FOLLOWED BY DEWATERING THE COATING AND CURING THE POLYMER.
 2. The method of claim 1 wherein said application of latex to the fabric is by spray application.
 3. The method of claim 1 wherein said fabric is a knit fabric.
 4. The method of claim 1 wherein said hydroxy lower alkyl acrylate is hydroxypropyl acrylate.
 5. The method of claim 1 wherein said alkyl acrylate is n-butyl acrylate.
 6. The method of claim 1 where said latex composition comprises said polymer and a polyfunctional organic compound reactive with the carboxyl or hydroxyl groups thereof to crosslink said polymer.
 7. The method of claim 6 wherein said polyfunctional organic compound is a water soluble melamine resin. 